.btn {
    /* 文字颜色 */
    color: #009688;
    /* 清除背景色 */
    background: transparent;
    /* 边框样式、颜色、宽度 */
    border: 2px solid #009688;
    /* 给边框添加圆角 */
    border-radius: 6px;
    /* 字母转大写 */
    border: none;
    color: white;
    padding: 6px 16px;
    text-align: center;
    display: inline-block;
    font-size: 10px;
    margin: 4px 2px;
    -webkit-transition-duration: 0.4s; /* Safari */
    transition-duration: 0.4s;
    cursor: pointer;
    text-decoration: none;
    text-transform: uppercase;
}
.btn1 {
    background-color: white;
    color: black;
    border: 2px solid #009688;
}
/* 悬停样式 */
.btn1:hover {
    background-color: #009688;
    color: white;
}
.btn2 {
    background-color: white;
    color: black;
    border: 2px solid #009688;
}
/* 悬停样式 */
.btn2:hover {
    border: 2px solid #e93030;
    background-color: #e93030;
    color: white;
}